Experiences applying H4 EAD while H4 extension in progress

[nytins]

Hi Guys,

My wife's H4 extension was filed in Sep 2018 at Vermont center. The site shows there is a 13-15 months processing time. Her H4 has expired in Dec 2018. My PERM petition is currently going on and I am hoping to get an I-140 approval by around April-May 2019. So that means I will have to still wait another 6-8 months before I get my wife's H4 extension approval. 

Has anyone applied for H4 EAD while H4 extension is in progress? If yes, could you please share your experiences?

Thanks in advance for your help.